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Biomedical subjects

D H Shah

Publications and source records attributed to D H Shah.

At least 55 records · Page 3Linked to original sources
PubMed1983

Immunoreactive thyroglobulin-like material derived from saliva.

The presence of an immunoreactive thyroglobulin-like material in saliva from normal subjects and from 35 patients with thyroid carcinoma was detected by radioimmunoassay. The levels of this material in saliva were markedly elevated in patients with extensive metastases. Concentrated saliva samples from normal subjects and from patients with thyroid carcinoma were fractioned on Sepharose-6B and each fraction was assayed from thyroglobulin content by RIA. Several protein peaks of varying molecular size with thyroglublin-like immunoreactivity were observed. The physiological significance of these molecules in saliva remains to be established.

Antibodies↗
PubMed1982

Disappearance rate of endogenously radioiodinated thyroglobulin and thyroxine after radioiodine treatment.

Endogenously radioiodinated thyroglobulin (tg) and thyroxine (T4), in the circulation following, therapeutic doses of radioiodine were studied in five patients with differentiated thyroid carcinoma. Radioactive serum was fractionated on a Sephadex G-200 and the various radioactive peaks thus obtained were analyzed for their biochemical and immunologic characteristics using precipitation with trichloroacetic acid (TCA) and antithyroglobulin antibody extraction with acidified n-butanol and electrophoresis on agar gel. The disappearance rates of endogenously labelled tg and T4 were 3.12 +/- 0.396 days and 10.14 +/- 1.81 days, respectively.

Adenocarcinoma↗
PubMed1982

alpha-Adrenergic agents. 2. Synthesis and alpha 1-agonist activity of 2-aminotetralins.

Substituted 2-aminotetralins are potent, selective, direct-acting agonists at postjunctional alpha 1 receptors. Within this series, substituent alterations on the ring, as well as on the nitrogen, change the potency of compounds by over three orders of magnitude (EC50 = 12 to greater than 10 000 nM). It has been demonstrated experimentally that substitution at both the 5 and 8 positions of the aromatic ring produces optimum agonist potency. Removal of either substituent results in a loss of potency and efficacy relative to norepinephrine. Substitution at positions 6 and/or 7 is generally detrimental to activity. Methyl, ethyl, or dimethyl substitution on nitrogen is compatible with high agonist potency, while substitution with larger groups is not. The most potent agonist in this series is 5-(thiomethyl)-8-methoxy-2-aminotetralin, which has an EC50 of 12 nM.

Adrenergic alpha-Agonists↗
PubMed1981

Alpha-adrenergic agents. 1. Direct-acting alpha 1 agonists related to methoxamine.

A series of phenylethylamines related to methoxamine has been prepared and evaluated for direct alpha 1-receptor agonist activity. It has been observed that for open-chain compounds such as methoxamine, in which the amine-containing portion is free to adopt numerous conformations, an hydroxyl group is necessary for direct alpha 1-adrenergic activity. When the hydroxyl is removed, however, the direct component of activity is greatly reduced unless the amine is incorporated into a more sterically defined structure. From our studies we have concluded that in order for a phenylethylamine to be active as a direct alpha 1-receptor agonist it should have a beta nitrogen in a fully extended conformation relative to a substituted phenyl ring. For optimum potency, the nitrogen should be exocyclic to a saturated six-membered ring. It may be further incorporated exocyclic or endocyclic into an additional ring as long as the amine occupies a well-defined region of space relative to the aromatic portion of a molecule. The ED50 values of some of the more potent compounds as alpha 1-receptor agonists are on the order of 1 X 10(-7) M.

Adrenergic alpha-Agonists↗
PubMed1981

Serum thyroglobulin differentiated thyroid carcinoma: histological and metastatic classification.

Serum thyroglobulin (tg) levels were measured in 112 patients with proved differentiated thyroid carcinoma (6 pre-operative, 32 post-operative and 74 in whom thyroidectomy was followed by radioiodine treatment). The tg levels were within the normal range in patients who had a residual mass in the neck region after surgery and who were in remission. The patients with metastases showed a wide range (undetectable to microgram quantities) of tg in circulation. The analysis of serum tg with respect to histology showed that the follicular variety of carcinoma tends to show higher tg in serum than the papillary type. Metastatic involvement of bone was associated with much higher serum tg levels than other sites such as lung and lymph node. Thirteen patients with bone metastases of non-thyroidal primary origin had tg levels within the normal range. Serum tg estimation is useful in excluding thyroid as a primary site in patients with bone metastases of unknown primary origin.

Adult↗
PubMed1980

Modifications in biphasic liquid-scintillation vial system for radiometry.

Several modifications of the biphasic liquid-scintillation vial system for radiometry have been tried in order to improve the counting efficiency. The biphasic system consisted of an inner sterile vial containing medium and substrate, and an outer liquid-scintillation vial lined on the inside with filter paper impregnated with scintillation fluors and alkali. The system gave an overall counting efficiency of 14.6%. Substitution of methanolic NaOH for impregnation of the paper raised the counting efficiency to 29.1%. This could be further enhanced to 33.8% by lining only half of the outer vial with filter paper, thereby allowing improved optical transmission of scintillation light. Increasing the amount of fluor did not change the efficiency significantly. A complete interchange in the system, whereby half of the inner vial was lined with filter paper and was otherwise empty, while the outer vial contained the medium and substrate, gave the highest efficiency (36.9%). This also allowed the use of larger amounts of medium and the inoculum.

Carbon Dioxide↗
PubMed1980

Radiorespirometric testing of antibiotic sensitivity in urinary tract infections: concise communication.

A radiometric method, based on inhibition of 14CO2 release from bacterial metabolism of C-14-labeled glucose, was applied to test the susceptibility of urinary organisms to antibiotics. The testing was also carried out by the routine disc diffusion method after isolation of the organisms. Results of susceptibility to antibiotics could be obtained within 2 to 4 hr by the radiometric technique, compared with the 48 hr required for the disc method.

Anti-Infective Agents, Urinary↗
PubMed1979

Pyranenamines: a new series of antiallergic compounds.

Condensation of 3,5-diacylpyrantriones with various aromatic amines gave a new class of potent, orally active, antiallergic compounds, the 3-[(arylamino)ethylidene]-5-acylpyrantriones, hereafter referred to as pyranenamines, as evaluated not only in the traditional rat passive cutaneous anaphylaxis (PCA) assay but also in the in vitro fragmented rat and primate lung assay. Potencies in the PCA system, when measured intravenously, reached a maximum ID50 of 0.9 mu/kg (1000 times more potent than disodium chromoglycate) with 5-acetyl-4-hydroxy-3-[1-[(3,5-bis-glyceramoylphenyl)amino]ethylidene]-2H-pyran-2,6(3H)-dione (100), as predicted by structure-activity relationship (SAR) analysis. Potencies in the iv PCA system correlated well with potencies in the in vitro rat lung system but not with potencies in the oral PCA system or the in vitro primate lung system. Several compounds had good oral potency, and one analogue, 3-acetyl-4-hydroxy-3-[1-[3-amino-4-hydroxyphenyl)amino]ethylidene]-2H-pyran-2,6(3H)-dione hydrochloride (78), reached an oral ID50 of less than 1 mg/kg and was better than 10 times more effective than disodium chromoglycate at inhibiting the release of histamine and slow-reacting substance of anaphylaxis in the fragmented primate lung assay.

Administration, Oral↗